1. Field
The present disclosure relates to circuit interrupting devices. In particular, the present disclosure is directed to re-settable circuit interrupting devices and systems that comprises ground fault circuit interrupting devices (GFCI devices), arc fault circuit interrupting devices (AFCI devices), immersion detection circuit interrupting devices (IDCI devices), appliance leakage circuit interrupting devices (ALCI devices), equipment leakage circuit interrupting devices (ELCI devices), circuit breakers, contactors, latching relays and solenoid mechanisms. More particularly, the present disclosure is directed to circuit interrupting devices that include a circuit interrupter that can break electrically conductive paths between a line side and a load side of the devices.
2. Description of the Related Art
Many electrical wiring devices have a line side, which is connectable to an electrical power supply, and a load side, which is connectable to one or more loads and at least one conductive path between the line and load sides. Electrical connections to wires supplying electrical power or wires conducting electricity to the one or more loads are at line side and load side connections. The electrical wiring device industry has witnessed an increasing call for circuit breaking devices or systems which are designed to interrupt power to various loads, such as household appliances, consumer electrical products and branch circuits. In particular, electrical codes require electrical circuits in home bathrooms and kitchens to be equipped with circuit interrupting devices, such as ground fault circuit interrupting devices (GFCI), for example.
In particular, GFCI devices protect electrical circuits from ground faults which may pose shock hazards. To prevent continued operation of the particular electrical device under such conditions, a GFCI device monitors the difference in current flowing into and out of the electrical device. Load-side terminals provides electricity to the electrical device.
A differential transformer measures the difference in the amount of current flow through the wires (i.e.—hot and neutral) disposed on the primary side (or core in the case of a toroid differential transformer) via a current signal analyzer, when the difference in current exceeds a predetermined level, e.g., 5 milliamps, indicating that a ground fault may be occurring, the GFCI device interrupts or terminates the current flow within a particular time period, e.g., 25 milliseconds or greater. The current may be interrupted via a solenoid coil that mechanically opens switch contacts to shut down the flow of electricity. A GFCI device includes a reset button that allows a user to reset or close the switch contacts to resume current flow to the electrical device. A GFCI device may also include a user-activated test button that allows the user to activate or trip the solenoid to open the switch contacts to verify proper operation of the GFCI device.
Presently available GFCI devices, such as the device described in U.S. Pat. No. 4,595,894 (the '894 patent) which is incorporated herein in its entirety by reference, use an electrically activated trip mechanism to mechanically break an electrical connection between the line side and the load side. Such devices are resettable after they are tripped by, for example, the detection of a ground fault. In the device discussed in the '894 patent, the trip mechanism used to cause the mechanical breaking of the circuit (i.e., the conductive path between the line and load sides) includes a solenoid (or trip coil). A test button is used to test the trip mechanism and circuitry used to sense faults, and a reset button is used to reset the electrical connection between line and load sides.
In addition, intelligent ground fault circuit interrupting (IGFCI) devices are known in the art that can automatically test internal circuitry on a periodic basis. Such GFCI devices can perform self-testing on a monthly, weekly, daily or even hourly basis. In particular, all key components can be tested except for the relay contacts. This is because tripping the contacts for testing has the undesirable result of removing power to the user's circuit. However, once a month, for example, such GFCI devices can generate a visual and/or audible signal or alarm reminding the user to manually test the GFCI device. The user, in response to the signal, initiates a test by pushing a test button, thereby testing the operation of the contacts in addition to the rest of the GFCI circuitry. Following a successful test, the user can reset the GFCI device by pushing a reset button.
Examples of such intelligent ground fault circuit interrupter devices can be found in U.S. Pat. Nos. 5,600,524, 5,715,125, and 6,111,733 each by Nieger et al. and each entitled “INTELLIGENT GROUND FAULT CIRCUIT INTERRUPTER,” and each of which is incorporated herein by reference in its entirety. Additionally, another example of an intelligent ground fault current interrupter device can be found in U.S. Pat. No. 6,052,265 by Zaretsky et al., entitled “INTELLIGENT GROUND FAULT CIRCUIT INTERRUPTER EMPLOYING MISWIRING DETECTION AND USER TESTING,” which is incorporated herein by reference in its entirety.